Smelly septic tank water quietly cleansed for reuse

December 12, 1993|By Liz Atwood | Liz Atwood,Staff Writer

The wind blows through the cattails and bulrushes, deer peer from the forest and a red fox watches from a den burrowed into a hill on 100 acres in southern Anne Arundel County that is essentially a sewage treatment plant.

It is the Mayo Peninsula Water Reclamation Facility, where rancid-smelling water from household septic tanks is turned into clean, odorless water without the roar of aerators and the hum of ventilators.

"Instead of hearing machines, you hear only the wind," said facility manager Gregory J. Swartz as he looked over a plot of marsh grasses.

The $62 million experimental system was built between 1986 and 1988 to appease Mayo Peninsula residents and state officials. Residents feared the extension of public sewers would lead to uncontrolled development, and state officials ordered the county build the sewers because of frequent failures of private septic systems in the area.

County officials and residents say the system, built to serve 2,190 homes, has been a success in its first five years of operation.

It is being expanded to serve an additional 585 dwellings.

Leon and Beverly Johnson had owned a historic home off Loch Haven Road only a few weeks when they learned that the county was planning to build a sewage treatment facility only a few hundred yards from their home.

"We were very upset," Mrs. Johnson said.

But as it turns out, the Johnsons say they are happier that their neighbor is a sewage treatment plant, rather than a housing development.

"If we knew then what we know now, we would still buy the house," Mrs. Johnson said. "We're amazed at how very seldom it bothers us."

All of the components of the treatment system have been used before, but their combination is unique, said Robert S. Kraft, chief of Anne Arundel's inspection division.

Sewage collects in 1,000-gallon septic tanks under the ground of each home or business in the system. Solids that settle to the bottoms of the tanks are cleaned out periodically and the water is pumped to collecting stations, then to the treatment plant.

The water first is filtered through a coarse sand where microscopic organisms begin to devour the pollutants. After about eight hours of circulating through the sand, the water is channeled to artificial marshes where cattails and bulrushes help to further purify it.

The water then is disinfected as it passes under ultraviolet lights. Next, it is sprayed into an artificial peat marsh to remove phosphorus. The water again passes under the ultraviolet lights before being released into the Rhode River three miles away.

The Mayo facility can process 468,000 gallons of water a day. When the expansion is completed in July, it will be able to process 585,000 gallons. The facility's total future capacity is approximately 950,000 gallons.

Since the county opened the plant, only two design changes have been needed. Plant operators have switched to a more coarse sand to filter the water and soon will begin adding chemicals to reduce the phosphorus content of the water.

The system's innovative design enabled the county to receive $45 million in state and federal grants to help defray construction and installation costs.

The first residents served by the system benefited from the grants and had to pay only $3,300 for the septic tank. But owners of new homes that will be served by the expansion will have to pay about $8,000 for the installation. In addition, the residents -- like all residents served by county sewer service -- pay $268 a year in service fees.

Mr. Swartz said that the Mayo plant has provided lessons in ecology as well as engineering during its first five years. Operators became concerned when caterpillars began to appear the artificial marshlands, but soon other insects that prey upon the caterpillars appeared.

Hawks, eagles and deer discovered the area as well. At the end of the system in the Rhode River, water grasses have started to return.

"I think everyone is very, very pleased with the facility," said Gordon Hamilton, who represents the Loch Haven Civic Association on a citizens advisory committee.

When Mr. Hamilton attended his first community meeting on sewer service, he found the atmosphere much like that of a "vigilante group," he said.

Emotions have since calmed, although residents are still concerned about development of the peninsula, said Edna Schmitt, president of the Mayo Civic Association. "If the sewerage installation goes as planned, it will let us grow at a slow rate."